Kidney Biopsy

My doctor told me I need a kidney biopsy. What does this mean?

Your doctor wants to take a tiny piece of your kidney to use for special tests. The test results will help your doctor decide what treatment you need to help your kidneys work properly and to anticipate your kidney function and progress in the future.

How is a kidney biopsy done?

One type of kidney biopsy is called percutaneous (through the skin) biopsy. A thin needle is passed through the skin into the area of the kidney. Inside the needle is a sharp cutting edge that slices and removes small pieces of the kidney. Another type of biopsy is called open kidney biopsy. This requires surgery rather than a needle.

Why are kidney biopsies done?

Kidney biopsies are performed for several major reasons:

• To identify a specific disease process and to determine whether it may respond to treatment
• To evaluate how much damage has occurred in the kidney
• To find out why a kidney transplant may not be doing well.

This information helps the doctor plan what treatment is needed.

What does a kidney biopsy involve?

The kidney biopsy can be done with the patient fully awake, under light sedation or under general anesthesia. A local painkiller is injected into the skin to minimize pain where the biopsy needle will enter. Generally, only mild discomfort is felt. The biopsy usually takes 30 to 60 minutes. In that time the kidney is located, the entry site is sterilized, the anesthetic is injected and the tissue is removed.

For the biopsy, you will be lying face down on your stomach with a pillow under your rib cage. However, if the biopsy is being done on a transplanted kidney, you will be lying on your back. The kidney is located using ultrasound and/or X-ray. Sometimes, intravenous dye is needed to help locate the kidney.

Once the site of entry to the kidney is marked, you receive a local painkiller and the biopsy needle is inserted. You need to take a deep breath and hold it while the kidney tissue is entered. When the needle pushes through the kidney to obtain tissue, you may feel a "pop" or pressure sensation. It is important to remain still and hold your breath until told to exhale (usually 45 seconds or less). At least two needle "passes" are needed to obtain enough tissue for diagnosis.

Once enough kidney tissue is obtained, the needle is removed and a bandage is placed over the biopsy puncture site.

Are there special preparations or follow up for a kidney biopsy?

For two weeks before the biopsy, you should avoid aspirin or over-the-counter pain medicines [LINK to analgesics] such as ibuprofen-type medications (Motrin, Advil, Ibuprofen P, etc.) These medicines may change normal clotting of the blood and increase the risk of bleeding with biopsy. A urine culture is usually done before biopsy to make sure the kidney is free of infection. The doctor will give you any other specific instructions when scheduling the biopsy date.

Kidney biopsies are usually done in the hospital with an overnight stay to watch for any complications after the procedure. After the biopsy, you need to stay in bed for 6 to 12 hours, or as directed by the doctor. Your blood pressure and pulse are checked often to look for any signs of internal bleeding. Blood counts are also done. You may eat and drink fluids after the biopsy. If you have stable blood counts, blood pressure and pulse, you may be able to leave the morning after the biopsy.

The doctor will advise you about physical activity and symptoms to look for after going home from the hospital. Heavy lifting, strenuous exercise and sexual intercourse should be avoided for two weeks after the biopsy. If you are constipated, it is important that you do not strain to have a bowel movement. Ask your doctor to prescribe a stool softener or laxative. You should call the doctor if any of the following occurs: